2 o'clock in the morning.

There are no street lights, and occasionally a car passes by on the road, with bright headlights and a piercing sound.

It can be hard to make great work when its stolen from bit.ly/3iBfjkV.

The stars in the sky are scattered, and there are probably a few more than what you would see in the city. But few people bother to look up, and even fewer have the leisure to count the stars. Even the children bury their heads in their desks, with no thoughts to spare.

There is still a hot and restless atmosphere in the surroundings, not the actual temperature, but more of a sense of anxiety.

It's like those workers who have just finished their night shift, their faces full of exhaustion.

The vendors selling late-night snacks on the roadside also have their faces stiff, and they half-heartedly beckon people, only to retract their arms.

The stray dogs wandering around, looking at the passersby, are too lazy to beg for food. Those who finish work at this time lack the enthusiasm and initiative to feed the dogs, and they are not willing to take the risk of being cute.

Among the passersby, many are looking at their phone screens. Some people are still holding their phones while riding electric bikes, swaying the handlebars left and right, without paying attention. Occasionally, they lose their balance and stop by the roadside to look at their phones before continuing on.

In the yard of the elderly scavenger, the glaring white lights are turned on. It should have attracted many onlookers, but most people just take a photo and leave, lacking interest in gathering around.

There are too many hot topics and too many melons, and everyone is too busy to keep up.

The locals in the city don't really care about what happens in the urban village. Those who like to post on social media and share videos are not willing to locate themselves in the urban village.

The death of an elderly scavenger did not cause any waves.

Jiang Yuan couldn't help but recall the life in Jiang Village before it was demolished. At that time, although everyone was poor, they had a lot of time.

Lazy and poor, there was a leisurely and pleasant atmosphere.

But life in Longli County's urban village is different. The people here are not only poor, but they also have no time.

The entire urban village is the result of demolition and relocation.

There is no hope.

The air is filled with exhaustion and helplessness.

The young people who returned to their hometown to start a business didn't get much besides the proximity to their families.

Jiang Yuan sat under a tree and drank a bottle of water, still feeling very tired.

But he was young and didn't feel like he was about to drop dead. He should be able to stay up all night.

Jiang Yuan looked at the technicians from the Criminal Science and Technology Brigade of Longli County not far away, feeling helpless. They were diligent and busy, like worker ants in an anthill, but their work seemed endless.

Jiang Yuan couldn't help but sigh.

The skills of these technicians are probably only at level 0.8 at most.

If they were diligent enough, the probability of finding the killer's DNA in a limited area would be very high, assuming the killer did leave DNA behind.

But human energy is limited, especially when focusing on details for a long time, it is still quite difficult.

The yard of the elderly scavenger is almost like a Rubik's Cube.

If it were a different case, the evidence might not be so obvious.

In an ordinary family, when an ordinary husband abuses an ordinary wife and causes her death, the ordinary living environment is usually at a 2D level.

If the entire house is customized and the murder happens in a room that is fully customized, it would be equivalent to a 3D level.

Assuming the full customization cost 150,000 yuan, then killing someone in a fully customized room would waste an additional 50,000 yuan of the police's investigation budget, at most.

But what is the structure of the elderly scavenger's yard?

It's 4D!

Not only does it have a plane and height, but there are also bloodstains and DNA information between objects.

In other words, when wiping the evidence in the elderly scavenger's yard, you not only have to wipe the surface, but also pick up those complex objects and wipe the inside.

The place where the elderly scavenger was beaten has been repeatedly impacted, repeatedly covering up the previous evidence, creating a staggering complexity.

If you want to be more meticulous, you also have to consider the factor of time, because the objects fell at different times, with different sequences. This means that they would have come into contact with different evidence at different times.

Lastly, and most importantly, even if these technicians with a level of 0.8 can wipe the killer's DNA, how can they prove whether it was contaminated on the day of the incident or before?

If it were Jiang Yuan's level 4 crime scene investigation, he might have some ways to differentiate, but for technicians below level 1, it's just wishful thinking.

And even if Jiang Yuan had a level 4 crime scene investigation, he didn't want to use it to make such distinctions.

It's too complicated. How can he explain it to judges and prosecutors during the legal process?

Therefore, the best way to prove it, Jiang Yuan believed, was to focus on the bloodstains and the murder weapon.

Furthermore, despite the fact that this group of men is exhausted from wiping DNA, their achievements are even harder to utilize than wiping DNA.

Jiang Yuan decided to save them... and save himself.

Jiang Yuan returned to the yard of the elderly scavenger, stood at the door, and looked at the busy technicians. He cleared his throat and said, "I have an idea."

The group of technicians, who had already become numb, stared at Jiang Yuan with lifeless eyes.

"I want to prioritize the search for bloodstain evidence and see if we can find the bloodstains left by the killer."

Seeing everyone looking at him, Jiang Yuan continued:"If it's not possible, we can also use bloodstain morphology analysis to determine which objects the killer came into contact with at the crime scene, thus narrowing down the scope of DNA testing."

Bloodstain morphology analysis is equivalent to reconstructing the crime scene.

By reconstructing the crime scene, we can "see" the killer's movement route in the scavenging courtyard and most of their actions.

As a result, objects that are closer to the killer have a greater chance of being contaminated with their DNA.

The expressions of the technicians went from numbness to a bit of excitement and then back to numbness.

"This is different from the task assigned to us by the criminal investigation team."

Hou Xiaoyong, one of the technicians, spoke first.

Jiang Yuan calmly said, "The tasks given to you by the criminal investigation team cannot possibly involve wiping DNA in a certain order. Conducting on-site investigations inherently involves prioritizing and making decisions. It should not be within the scope of on-site investigations to determine how to handle it."

The technicians were not assertive and did not expect the young forensic from the neighboring county to be so assertive.

One of the older technicians, Lao Li, couldn't help but stand up, took the opportunity to stretch his waist, twisted a bit, and said, "Xiao Jiang, what if we miss or contaminate the DNA using your method? Who will take responsibility?"

The other young technicians from Longli County felt a bit embarrassed and lowered their heads. They were already lacking in technical skills, and on one hand, their skills were not up to par, and on the other hand, their ability to kick the ball was too strong.

Now they had to hand the ball to the forensic expert from another county for help. The young technicians still had thin skin, especially since they had just eaten the food Jiang Yuan gave them and smoked his good cigarettes.

"In the current environment, which DNA hasn't been contaminated?" Jiang Yuan sneered.

Two of the technicians couldn't help but laugh.

Indeed, in this crime scene, what's the point of talking about contamination? The objects collected from scavenging were all covered in unknown DNA.

So many people...

The tall and young Jiang Yuan was still quite eye-catching among the group.

He confidently said, "In this kind of environment, bloodstains are the most effective in proving identity. Since it's all a gamble, if you ask me, I would definitely bet that the bloodstains contain the killer's DNA. Furthermore, betting on bloodstain morphology analysis is better than betting on the crime scene."

The other technicians looked at each other, hesitating. They didn't want to wipe DNA like this and end up doing useless work, only to be scolded in the end.

"Moreover, by starting with bloodstains, we can preserve the most important evidence first. Anyone conducting on-site investigations and making this decision is absolutely correct. No matter where it is reviewed, there won't be a single mistake. Or, you can make a phone call to consult?"

Although Jiang Yuan was young, he wasn't impulsive. He came to help, not to take the blame. He kicked the ball back.

The technicians also leaned towards Jiang Yuan's words.

Having a direction is better than blindly working hard here.

The young technician, Hou Xiaoyong, asked again, "Forensic expert Jiang, can you reconstruct the crime scene?"

"Yes."

Jiang Yuan's answer was short and powerful.

"Reconstructing the crime scene is not easy..." Hou Xiaoyong couldn't help but mutter.

If we talk about who is closest to bloodstain morphology analysis, it would naturally be Hou Xiaoyong, who does on-site investigations. However, he only knows some superficial knowledge, and he is far from being able to reconstruct the crime scene like those experts on TV. In reality, it's very rare, and some of it is exaggerated.

Reconstructing the crime scene is no longer just a matter of ability. It also involves face, image, and even status.

When it comes to solving cases in reality, reconstructing the crime scene means reconstructing the scene of the killer's murder or attack. Although it sounds cool, the on-site investigation needs to be completed step by step, and the process needs to be detailed in a report of thousands of words.

Then comes the possibility of facing the killer's soul-crushing feedback.

If any on-site investigator receives such feedback from the killer, their emotions would definitely collapse.

The mocking laughter from the team, there's no need to think about it.

Therefore, even if an on-site investigator knows a little about reconstructing the crime scene, they wouldn't dare to do it if they are not skilled.

After completing it, should they pray to catch the killer or pray to kill the killer on the spot?

Only a very small number of people can successfully pass the probation period of reconstructing the crime scene.

And when these people become well-known, they are usually already experts.

Hou Xiaoyong suspected that Jiang Yuan didn't know about the various problems he would face in reconstructing the crime scene.

After all, Jiang Yuan is younger than him.

But on second thought, only when the reconstruction fails or is done incorrectly will they face these problems. If the reconstruction is successful, the so-called problems won't be problems anymore.

Considering Jiang Yuan's expertise in fingerprint analysis, Hou Xiaoyong didn't dare to speak recklessly.

The technicians present also knew that the county only borrowed Jiang Yuan because he was young, and it was done under the guise of borrowing a forensic expert.

After borrowing him, they didn't even let him see the body and sent him directly to the crime scene. What the county really wanted to borrow was Jiang Yuan's fingerprint skills.

With this in mind, Hou Xiaoyong said, "Forensic expert Jiang, if you say you need to change the order of on-site investigations for fingerprint collection or something, I think it would be easier for the higher-ups to agree."

He was basically suggesting to Jiang Yuan how to make the application.Jiang Yuan pretended not to understand. At this moment, the same sentence could work again - he was not from Longli County, and it would be even more inappropriate for him to apply to the leaders.

"You can consult the leaders, or we can just do it this way." Jiang Yuan felt either way was fine.

As he said, leaders usually ask technicians to find clues, fingerprints, and DNA at the scene. Few leaders would be meticulous enough to arrange the order of the scene investigation.

He also needed to understand this.

"How long do you need?" Hou Xiaoyong asked.

"Until morning, six hours should be enough." Jiang Yuan glanced at his watch (a simple and unadorned nautilus), which put the time at over 8 o'clock in the morning.

Hou Xiaoyong took a look and felt inexplicably close. Young people who still wear watches nowadays give a more mature and steady impression.

"I'll call Team Leader Zheng from the Zhong'an Squad. If he wants to report to the head of the brigade, let him report."

Hou Xiaoyong didn't want to call Hou Lejia, the head of the brigade, for such a thing at two o'clock in the morning. Even though they were relatives, there was no need to disturb his sleep.

In a while, Hou Xiaoyong finished the call and returned.

Everyone was standing there waiting.

"Team Leader Zheng has no objections, let's do it." Hou Xiaoyong said.

"Let's try to finish within five hours, leaving some time for tidying up." The most senior technician, Old Li, compromised a bit.

"Okay." Jiang Yuan agreed immediately.

"What do you want us to do?"

Senior technician Old Li, in fact, also respected Jiang Yuan as a fingerprint expert, and asked him what to do.

Anyone who can solve ten murder cases, no matter by what means, is a badass in the police force.

Battle achievements are ultimately earned.

And in the police force, solving cases is the greatest achievement.

"Start from the entrance."

Jiang Yuan decisively said.

He simply returned to the entrance.

Starting from the beginning, he walked step by step, saying:

"The murderer followed in, brought his own weapon, and closed the door..."

"Why?" Hou Xiaoyong asked after hearing the first step.

Like a student who actively asks questions.

Jiang Yuan put on his gloves, gently closed the door, and said:

"Because there are bloodstains on the back of the door. If the door wasn't closed, the outside of the door should be stained with blood. Of course, this bloodstain was caused later."

Hou Xiaoyong exclaimed, then understood.

With this explanation, he understood clearly, but he hadn't thought of this just now.

The others also nodded in sudden realization.

"We can collect trace evidence here later, which will help analyze the type of weapon. But for now, let's follow the murderer's steps..."

Jiang Yuan pointed ahead and said, "The murderer knocked the old man to the ground, then swung the weapon to attack..."